A Detailed Guide to the Latest Control Methods for Asparagus Stem Blight
Asparagus is a stem vegetable that people commonly eat, and the occurrence of stem blight during cultivation can cause severe yield reductions. Stem blight is also called the cancer of asparagus; in mild cases it reduces yield, and in severe cases it causes total crop failure, bringing huge losses to growers. So how should asparagus stem blight be controlled? Follow the editor and take a look.
1. Disease symptoms
The pathogen of asparagus stem blight infects and damages tender stems and tender branches. After infection by the pathogen, needle-like milky white spots the size of pinpoints first appear at the infection site, gradually expanding into small spindle-shaped or fusiform water-soaked spots. The spots gradually turn brown, with a grayish-brown center, sunken and scattered with small black dots, namely the pycnidia. When the spots are severe, they cover the entire plant. When a spot encircles the stem completely, the whole plant dries up and dies.
2. Occurrence pattern
In cold winter, the aboveground part of asparagus dies back, and the pathogen overwinters on diseased residues as mycelium and conidia. In spring, when temperature and humidity are suitable, conidia are produced from the pycnidia for primary infection. In greenhouse cultivation, because asparagus grows all year round, this also provides favorable conditions for asparagus stem blight. The pathogen does not undergo overwintering dormancy and primary infection, and multiple infection cycles can occur throughout the year.
3. Control methods
1. Choose disease-resistant varieties
To control stem blight, start from the source. Before raising seedlings, first disinfect the seeds to control the stem blight pathogen, and take preventive measures during seedling management. Observe frequently, and spray carbendazim and mancozeb once every half month as preventive chemical control. At the same time, also control aphids, thrips, armyworms and other larvae.
2. Do a good job of clearing the garden
Clearing the garden in winter is a key step in preventing asparagus disease. Whether the garden is cleared promptly and thoroughly plays a decisive role in the incidence of stem blight the following year. The best way to control stem blight is to reduce the pathogen population, and the way to reduce the pathogen population is to clear the garden.
3. Rain-shelter cultivation in greenhouses
Rain-shelter cultivation in greenhouses is the most effective method for controlling asparagus stem blight. Using greenhouse cultivation, first, it can prevent rainwater from entering the greenhouse and block its transmission route; second, it can regulate temperature, prevent premature aging of plants, and improve immunity; third, fumigant fungicides can be used, greatly reducing manpower, material resources and financial costs; fourth, it significantly extends the harvest period and increases yield.
4. Chemical control
The main chemicals that can be used to control stem blight include carbendazim, mancozeb, chlorothalonil, Bordeaux mixture, etc. To avoid the development of resistance, different chemicals should be used alternately.
The above is an introduction to the control methods for asparagus stem blight. We hope it can help you. To learn more related knowledge, please follow us.